Technological innovations in musculoskeletal disease care are a major contributor to Medicare spending growth, which is widely recognized as unsustainable. The proposed research will provide policy-relevant evidence on the comparative clinical effectiveness, safety, and economic value of emerging devices/biologics to treat common back-pain-related degenerative spine conditions in the elderly. The project methodology is based on an innovative combination of Dartmouth's unique expertise in Medicare claims-based health care epidemiology, model-based cost-effectiveness analysis, and data from a major prospective clinical trial in spine disease. Three specific aims are proposed: Aim 1 links Medicare claims data to detailed patient-level data from the Spine Patient Outcomes Research Trial (SPORT) to study utilization and safety of spinal fusion surgery as performed for different underlying conditions in the Medicare population. We hypothesize that the rapid growth in lumbar fusion surgery has occurred for conditions where the evidence for its effectiveness remains uncertain, and the proposed study will provide needed information to evaluate the consequences of such care. Aim 2 addresses the safety and efficiency of lumbar fusion surgery for degenerative spondylolisthesis, a condition where the safety and value of alternative types of fusion surgery and use of biologics to augment fusion remains controversial. Aim 3 characterizes diffusion, safety, costs and the cost-effectiveness potential for an emerging device for minimally invasive surgical treatment of spinal stenosis;again linking claims data with data from the SPORT multi-center trial. By examining the impact of changing care technologies on complications and costs of treatments for degenerative spinal conditions and integrating these findings into model-based cost-effectiveness analyses, the proposed research will identify ways to improve the efficiency and safety of musculoskeletal disease care.